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GATE 2023 IN – Question 8

General Aptitude · Analytical Aptitude: Logical Reasoning and Deduction · 2 marks · Multiple choice

The information contained in DNA is used to synthesize proteins that are necessary for the functioning of life. DNA is composed of four nucleotides: Adenine (A), Thymine (T), Cytosine (C), and Guanine (G). The information contained in DNA can then be thought of as a sequence of these four nucleotides: A, T, C, and G. DNA has coding and non-coding regions. Coding regions—where the sequence of these nucleotides are read in groups of three to produce individual amino acids—constitute only about 2% of human DNA. For example, the triplet of nucleotides CCG codes for the amino acid glycine, while the triplet GGA codes for the amino acid proline. Multiple amino acids are then assembled to form a protein.

Based only on the information above, which statements can be inferred with certainty?

(i) The majority of human DNA has no role in protein synthesis.

(ii) The function of about 98% of human DNA is not understood.

  1. only (i)
  2. only (ii)
  3. both (i) and (ii)
  4. neither (i) nor (ii)

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Correct answer: (D) neither (i) nor (ii)

Explanation

The passage identifies the directly translated coding fraction. It does not establish that other regions have no role in protein synthesis, or that their functions are unknown. Neither inference follows solely from the text.

Therefore **D**.